The present invention relates in general to tamper-evident closures for containers and in particular to tamper-evident buttress plugs for 55-gallon drums and related containers.
During the storage and transport of shipping receptacles containing materials such as liquid foodstuffs and chemicals, there is a risk that an unauthorized individual may gain access to the contents. In order to alert the recipient or end user to any possible tampering attempts, packagers and shippers have used tamper-evident closures. This type of closure typically includes frangible elements or tearable membranes or a pry-off cover or overseal which once defeated provides a visible indication of such tampering which cannot be replaced or mended back into its original form. The recipient or end user upon seeing the broken frangible elements or the cover removed is warned that unauthorized access to the contents may have occurred. The effect is to preclude the use of such foodstuffs or chemicals without careful checking to see if the contents are pure. Any container which is received with the tamper-evident feature intact gives an indication that tampering has not occurred and those containers do not have to be additionally inspected. Since these containers may include food or chemical ingredients which are only one part of a larger combination or mixture, it is imperative that the contents not be used if they are contaminated for both cost and safety reasons.
The options for tamper-evident closures are somewhat governed by the style of the container and its neck or pouring outlet. If the outlet is internally threaded, one style of closure will be selected while a different style will be required for externally theaded container outlets. Within each of these two basic styles, there are a number of variations as to the configuration and location of frangible elements, the use or absence of ratchet teeth and how these are applied to the closure and outlet.
Several of these varying styles are disclosed by one or more of the following prior references, some of which are believed to be representative of closures having tamper-evident styling.
______________________________________ Patent No. Patentee ______________________________________ 4,687,112 Swartzbaugh 4,666 063 Holoubek et al. 4,458,820 Abrams Re. 31,496 Keeler 4,153,174 Keeler 4,326,639 Stahl et al. 4,165,813 Babiol 4,081,097 Dold 4,062,466 Conti 4,019,663 Krautkramer 3,811,590 Hall, Jr. 3,074,580 Golde 2,940,627 Schultz 2,423,582 Coleman 2,134,178 Esposito 2,054,031 Conner et al. 1,901,196 Shera 1,891,033 Wackman ______________________________________
Swartzbaugh discloses a child-resistant package that includes a wide mouth blown glass container or blow-molded plastic container and a molded thermoplastic closure that is affixed to the finish portion of such container. The finish portion of the container has a radially outwardly projecting flange at the bottom portion of such finish portion and this flange has a notch in its outer periphery. The closure has a flexible projection that extends outwardly and downwardly from the skirt of the closure and a portion of this projection engages the notch in the flange of the finish to prevent the turning of the closure on the finish. This particular reference is typical of those closure designs which are intended more as a child-resistant scheme than a tamper-evident configuration. This particular closure may be reused and does not disclose any type of frangible elements or membranes which must be torn or broken in order to open the container.
Holoubek discloses a container with a twist-off tamper-evident feature which is disposed as an integral seal member formed across the outlet in the neck of a thermoplastic container. This seal member must actually be broken free from the neck in order to gain access to the contents. Torque is applied to the seal member by providing in the top of a conventional screw cap which forms a resealing closure for the container a recess with serration which, when the cap is removed and turned upside down, engage serrations on the peripheral edge of the integral seal member. This particular reference is of interest with regard to the present invention in that actual breaking or severing must be achieved in order to gain access to the contents of the container. However, this disclosure is different from the present invention in that the container itself is sealed and the severing of the seal is directly from the container rather than severing a portion of the closure from the remainder so that the remainder can be removed without altering or otherwise modifying the container style.
Abrams discloses a tamper-indicating arrangement for a container which functions to provide a visual indication that the container has been opened. This particular arrangement includes a closure which is adapted to be fitted to the container and includes first and second coacting means for respectively retaining the closure on the container in distinct first and second positions with respect to the container. In this way, the closure can be initially applied to the container in its first position and can only be reapplied and retained on the container in a reoriented second position. This particular disclosure is dissimilar from the present invention in that frangible elements are not provied which must be broken in order to remove the closure from the container.
Keeler (U.S. Pat. No. Re. 31,496) is a reissue of Keeler (U.S. Pat. No. 4,153,174) and these will be reviewed together in view of the common subject matter. Keeler discloses a tamper-proof closure for a container having a member projecting from its neck in which the closure is thermoformed with a skirt wall having a tab which engages the projecting member and which breaks off as the closure is unfastened from the container. This particular style of closure and container includes a container neck which is externally threaded and a closure which is internally threaded with the closure having a single tab 76 which engages segments 71 around the neck of the bottle with spaces therebetween. While this may be regarded as a ratcheting configuration, this particular type of closure is not styled nor arrranged nor structurally suitable for the necessary Department of Transportation (DOT) requirements for over-the-road transported 55-gallon drums as set forth in CFR 49, part 178.19, Spec. 34, is not molded in a fashion which creates special concerns as to the series of ratchet teeth around the neck and does not include frangible elements of the type disclosed in the present invention.
Stahl discloses a screw cap for bottle type containers and has the same deficiencies as previously noted for Keeler. Stahl is of some interest with regard to the present invention in that it includes a collar 20 which is joined to the cap by a plurality of shearable links 27, 29 in a circumferentially distributed arrangement to the outer circumferential surface of the top edge 12. Although these links are sheared off as part of the removal process, this particular reference does not disclose the configuration and interlocking ratchet teeth nor the style of frangible elements as presented by the present invention.
Babiol discloses a security closure device for bottles which includes a capsule screwed on the neck, a cap surrounding the capsule and a tearable guarantee strip. Although ratchet tooth engagement is disclosed, this occurs between an inner seal and outer cap and does not involve the neck of the container. This particular disclosure is also geared to a bottle cap configuration and is not styled nor suitable for use with the buttress plug requirements for transported 55-gallon drums which is the focus of the present invention.
Dold discloses a similar bottle cap style described as a safety closure for bottles with a thread on the neck and a bead arranged thereunder. This particular invention includes a screw cap and a safety ring fastened thereon with safety fracture stays. At least two teeth are arranged offset relative to one another by a circumferential angle on the neck of the bottle on the bead. At least to break-open pins which are offset relative to one another by a circumferential angle are joined on the lower edge of the screw cap.
Conti discloses a tamper-proof closure cap with a self-removing ring typical of the type currently seen on plastic milk bottles. The container closure cap is provided with a ring that breaks away from the cap in a strip as the cap is twisted open. Although this type of frangible ring and ratchet tooth engagement may have some similarity to aspects of the present invention, it is once again noted that the present invention focuses on buttress plug closures for transported 55-gallon drums and by that design must take into account and consideration the manufacturing style and configuration of the closure and the various DOT requirements for containers of this type. Conti, as typical of many of the references listed, simply is not styled for this type of closure and container combination. Consequently, many of the requirements are ignored and the overall design as presented by Conti is simply not suitable for the closure and container combination which is the focus of the present invention.
Krautkramer discloses separating means for plastic closure tops involving a plastic closure for a container which is molded in an integral single piece. This particular disclosuree includes a closure ring at the bottom which seats in the opening in the container a spout at the top of the closure, and above the spout is a dual-purpose closure element which seals the closure before its first use and after the closure element is initially torn loose, the closure element is thereafter placed in and removed from the spout to seal the spout. Integrally molded between the base of the closure element and the top of the spout is tear-off band having a removable handle such that drawing upon the handle removes the band and separates the closure element from the spout.
Hall, Jr. discloses a safety container closure for small plastic medicine bottles. A plug is inserted into the top or neck in a tight friction fit. The plug carries a key recess and the outer cap fits over the top of the container and carries a key molded to it. The key is placed into the recess in the plug engaged for withdrawal. An upper rib on the plug fits into a groove in the container to inhibit dislodgement. This particular disclosure once again is of conventional bottle and cap configuration and is not compatible with the transported 55-gallon drum container style of the present invention.
Golde discloses a closure for bottles wherein a portion of the closure is inserted down into the bottle mouth or outlet opening and the remainder of the closure extends over and around that opening. The closure is of an integral molded one-piece construction of a soft resilient plastic thereby making possible the insertion of this inward projecting sealing portion.
This particular disclosure does not include any type of frangible elements nor any type of closure container of the transported 55-gallon style and thus is believed to have limited relevancy to the present invention.
Also having limited relevancy is the patent to Schultz which is a champagne bottle closure and is provided herewith solely for its showing of a plug which fits into the interior of the neck opening and for its disclosure of an outer ring which must be defeated and removed from the closure plug in order to remove that plug from the container.
Coleman discloses a bottle cap and once again while its application to the present invention is quite limited, it does include a series of ratchet type teeth engagement where one set of ratchet teeth are disposed on the outer surface of the container neck. In contrast to the present invention, the engaging ratchet teeth are on the cap and not part of a separable frangible ring.
Esposito discloses a bottle cap which includes a series of ratchet teeth around the neck or outlet opening of the bottle and a removable engaging ring which is torn free in order for the bottle cap to be removed from the bottle. This particular invention includes a sheet metal screw cap and a bottle design which is not similar to the 55-gallon drums of the present invention.
Connor discloses a container closure of the conventional bottle and cap style wherein there is provided a breakable indicator member which may be formed to constitute a closure for the container. The readily breakable indicating member whether separate from the primary closure or otherwise is performed and adapted to be put in place on the container without substantial change in size or shape and is to be distinguished from various devices of the prior art consisting of sheet metal or paper or fabric or other material adapted to be crimped or folded or shrunk or otherwise put into place by change in size or shape.
Shera discloses a closure device for the filling and/or discharge openings of metallic containers such as drums, barrels and the like and is specifically directed to closure plugs for these types of containers. This particular patent discloses a style of prior art tamper-evident feature namely in the form of seal cap 18 which is applied over the outer bead or edge of the container outlet and completely covers the removable portion of the closure plug thereby precluding removal of the plug until this seal is defeated. This cap 18 is formed of relatively thin metal and once it is secured over the bead, it cannot be removed without protection and in fact without destroying its further usefulness. This patent also discloses an internal recess to the plug and wedge-shaped, diameterically opposed lugs which extend integrally from and radially inward of the inner wall of the plug and terminate short of the central portion thereof and are intended to be compatible with a wrench or similar tool for rotating the plug for advancement and removal.
Wackman discloses a sealing cap for the plugs of metal drums and the like wherein an overseal is applied and is constructed of lightweight resilient metal and this device also includes a hex recess for use with a wrench for advancing and removing the closure plug.
While the foregoing group of references may all fit within the general category of container or bottle closures and in many cases in the category of tamper-evident closures, they are not in any case suitable for meeting the DOT performance requirements (see CFR 49, part 178.19, spec. 34). There are specific drop test and hydrostatic requirements for closures used on large containers (55-gallon drums, etc.) which must be met if the container is transported over the road. None of the foregoing references are styled or designed to meet those requirements, and any containers which are suitably designed for those requirements do not have any tamper-evident features simillar to the present invention.
In order to provide a tamper-evident closure which is suitable for plastic 55-gallon drums and which meets all DOT and drop test requirements, a new design is required over what is presented by the foregoing group of references or otherwise available. This unique closure is provided by the present invention which also incorporates novel features in the design of the neck of the container outlet for a unique cooperating combination.